A timeline for T3H Metroid Galaxy has been put together from the various sources and dates within the series. Some of these years and dates may be assumed. All dates follow the Metroid series' Cosmic Calendar.
- The Writer and the original Future Writer are created from the author's bipolar personality. The Future Writer founds Pencilla, a planet for his followers.
- A Pencilla citizen named Jacob meets the dying God of All Things, who fuses their bodies to create Cronal, a being who rules Pencilla in the Future Writer's absence.
- The young boy who will become the new Future Writer is born on Pencilla.
- The young boy accidentally kills two bullies with electricity. Richard takes him to Cronal, who decides he will be the new Future Writer. The original Future Writer is killed by a giant robot.
- May 16, 2055: Samus Aran is born to Rodney and Virginia Aran.
- June 2055: His training complete, the new Future Writer is ordered to kill Samus. He meets the Writer on Pencilla.
- June 16, 2055: The Writer visits the Arans on Earth and learns they have discovered the Relics of the Old People. He returns to Pencilla and learns of the Future Writer's plan to kill Samus. He and the Future Writer race to the Arans' house after an incident resulting in the deaths of Sammy and Richard. The Future Writer kills Samus's parents but is imprisoned by the Relics of the Old People. The Writer takes Samus to the Chozo to be raised.
- Samus becomes a bounty hunter.
- February 2079: Samus goes to Zebes to fight Mother Brain. She meets many of the series characters, such as Oveur, Ridley, Kraid, and Dark Samus. She destroys Zebes.
- March 2079: Samus goes to Tallon IV with Oveur and defeats Dark Samus, disguised as Metroid Prime. Samus goes to Aether with Oveur and destroys the Ing infestation.
- April 2079: Samus and Oveur meet the Writer, Dracog, Pickett, and Bad Grammar Boy and go on a race to find the ten Relics of the Old People, inadvertently freeing the Future Writer. All the characters team up to defeat the Future Writer. Samus, Ovuer, and the Writer are locked in jail for a year because of their unruly and damaging behavior.
- May 2079: After only 23 days, the three are freed to stop Davy Jones, but locked back up again when finished.
- April 2080: Finally finished with their sentence, the three heroes crash land their plane on a deserted island and are eventually rescued by Peter Jackson, who makes a movie of their escapades. Samus and Oveur head to the Alimbic Cluster to find the eight Octoliths, fight off rival hunters, and defeat Gorea.
- May 2080: The three enter a race with the other characters, with the reward being a Jewel. Samus, Oveur, and the Writer are kidnapped by Mother Brain. The three retrieve their Jewel and another in Mother Brain's possession and escape. However, the Future Writer makes his return known. The characters team up again to obtain the last Jewel. However, the Future Writer steals all three and becomes a god. He is defeated after killing several of the characters.
- May 16, 2080: Samus's 25th birthday. The heroes join with a revived Future Writer to defeat Cronal. The Future Writer is killed in the attack.
- March 2081: The three team up again with other hunters to stop Dark Samus's Phazon plot. The Covenant arrive in the solar system. The Covenant invade Earth looking for the Ark, but the revived Future Writer both helps and harms their cause. The activated Ark is destroyed by Master Chief and kills the Future Writer. The three see Cloverfield in theaters and experience a parody of the events with a giant Mudkip.
- April 2081: The Writer explains the Duo Stone and the characters work together to obtain the first half, which the Future Writer steals. A massive war breaks out over the second half, which ends with the Future Writer obtaining it as well. However, Bad Grammar Boy steals it and becomes superpowerful, eventually being defeated by the characters.
- May 16, 2081: Samus's 26th birthday. Cronal returns but is defeated in the future.
- Cronal is defeated by past versions of Samus, Oveur, and the Writer. Future Samus is married to the Future Writer for unknown reasons.